Head-up display system

ABSTRACT

A head-up display system displays a virtual image superimposed on a real view that can be visually recognized through a window part. The head-up display system includes a display part, an optical system, a light source part, an operation part, and a controller. The controller controls a display area of the display part in accordance with an operation of the operation part by the observer. The light flux emitted from the display part is reflected by the window part and reaches a visually recognizable area where the observer can visually recognize the virtual image. The light emitted from the light source part is reflected inside an area where the light flux is reflected by the window part and reaches the visually recognizable area. The virtual image and the light from the light source part are superimposed, and can be visually recognized.

CROSS-REFERENCE TO RELATED APPLICATIONS

This is a continuation application of International Application No.PCT/JP2020/048252, with an international filing date of Dec. 23, 2020,which claims priority of Japanese Patent Application No. 2020-88969filed on May 21, 2020, the content of which is incorporated herein byreference.

BACKGROUND OF THE INVENTION 1. Technical Field

The present disclosure relates to a head-up display system that displaysa virtual image.

2. Description of Related Art

WO 2019/224922 A discloses a vehicle information projection system thatperforms augmented reality (AR) display using a head-up display device.The head-up display device projects light representing a virtual imageon a windshield of a vehicle to allow a driver to visually recognize thevirtual image together with a real view of an outside world of thevehicle. It is described that a position of an eye of a driver isdetected, and a superimposed display area in which the virtual image issuperimposed and displayed is changed in accordance with the position ofthe eye of the driver.

SUMMARY

However, in WO 2019/224922 A, in order to change the superimposed area,a tilt angle of a reflection mirror that reflects the image displayed bya display part on the windshield is adjusted. When the reflection mirroris rotated, a depression angle of the virtual image changes, and adeviation may occur in the superimposition between the real view of theoutside world and the virtual image.

The present disclosure provides a head-up display system capable ofadjusting a position of a virtual image in accordance with a height ofan eye of an observer to reduce a superimposition deviation between areal view of an outside world and the virtual image.

A head-up display system of the present disclosure is a head-up displaysystem that displays a virtual image superimposed on a real view thatcan be visually recognized through a window part, the head-up displaysystem including: a display part that emits a light flux to be visuallyrecognized by an observer as the virtual image; an optical system thatguides the light flux to the window part; a light source part that emitslight; an operation part for adjusting a position of the virtual imagein a vertical direction; and a controller that controls a display areaof the display part in accordance with an operation of the operationpart by the observer, wherein the light flux emitted from the displaypart is reflected by the window part and reaches a visually recognizablearea where the observer can visually recognize the virtual image, thelight emitted from the light source part is reflected inside an areawhere the light flux is reflected by the window part and reaches thevisually recognizable area, and the virtual image and the light from thelight source part are superimposed, and can be visually recognized.

According to the head-up display system of the present disclosure, theposition of the virtual image can be adjusted in accordance with aheight of an eye of the observer, and superimposition deviation betweenthe real view of an outside world and the virtual image can be reduced.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a view for describing a head-up display system.

FIG. 2A is a schematic view illustrating a configuration of a head-updisplay system in a first embodiment.

FIG. 2B is an explanatory view illustrating an optical path of lightemitted from a light source part.

FIG. 3 is an explanatory view illustrating an example of a displayablearea of a display part and a displayed image.

FIG. 4 is an explanatory view illustrating a range where an image is tobe superimposed and a displayable range of a virtual image.

FIG. 5 is an explanatory view illustrating a calibration image and abright spot of the light source part.

FIG. 6 is an explanatory view illustrating the calibration image and thebright spot of the light source part.

FIG. 7 is an explanatory diagram illustrating a flow of calibration ofvirtual image display in the first embodiment.

FIG. 8 is a schematic view illustrating a configuration of a head-updisplay system in a second embodiment.

FIG. 9 is a schematic view illustrating a configuration of a head-updisplay system in a third embodiment.

FIG. 10 is a schematic view illustrating a configuration of a head-updisplay system in a fourth embodiment.

FIG. 11 is a schematic view illustrating a configuration of a head-updisplay system in a fifth embodiment.

FIG. 12 is a schematic view illustrating a configuration of a head-updisplay system in a sixth embodiment.

FIG. 13 is a schematic view illustrating a configuration of a lightsource part in the sixth embodiment.

FIG. 14 is a schematic view illustrating a configuration of a lightsource part in a modification of the sixth embodiment.

FIG. 15 is a schematic view illustrating a configuration of a lightsource part in a modification of the sixth embodiment.

FIG. 16 is a view for describing a head-up display system in amodification of the first embodiment.

DETAILED DESCRIPTION First Embodiment

Hereinafter, referring to FIGS. 1 to 7 , a first embodiment will bedescribed.

[1-1. Configuration]

[1-1-1. Overall Configuration of Head-Up Display System]

A specific embodiment and an example of a head-up display system 1 ofthe present disclosure will be described. FIG. 1 is a view illustratinga cross section of a vehicle 3 on which the head-up display system 1according to the present disclosure is mounted. As illustrated in FIG. 1, a head-up display device (hereinafter, referred to as a HUD device) 9is disposed inside a dashboard 7 below a windshield 5 of the vehicle 3.An observer D recognizes an image projected from the HUD device 9 as avirtual image Iv. In this manner, the head-up display system 1 displaysthe virtual image Iv so as to be superimposed on a real view that can bevisually recognized through the windshield 5. In addition, a wall part13 extending upward from the dashboard 7 is provided. The wall part 13is, for example, a plate-like member.

FIG. 2A is a schematic view illustrating a configuration of the HUDdevice 9 according to the present embodiment. FIG. 2B is an explanatoryview illustrating an optical path of light Lg emitted from a lightsource part 15.

As illustrated in FIG. 2A, the HUD device 9 includes a display part 21,a projection optical system 22, a controller 23, a case 24 thataccommodates these components, and a transparent member 25 provided inan opening 24 a of the case 24. The opening 24 a of the case 24 isdisposed, for example, in accordance with a position of an openingprovided on an upper surface of the dashboard 7.

In the HUD device 9, the display part 21 is an optical member having adiffusion characteristic, and projects a light flux of an imagedisplayed on the display part 21 onto the windshield 5. The projectedlight flux is reflected by the windshield 5 as a window part and guidedto a visually recognizable area Ac of the observer D. Thus, the HUDdevice 9 causes the observer D to visually recognize the virtual imageIv. The visually recognizable area Ac is an area where the observer Dcan visually recognize the virtual image Iv without missing.

Here, in the present disclosure, a front direction is a direction inwhich the windshield 5 of the vehicle 3 exists as viewed from theobserver D. A rear direction is a direction opposite to the frontdirection. A lower direction is a direction of a ground on which thevehicle 3 travels. An upper direction is a direction opposite to thelower direction. A vertical direction is an up-down direction.

Here, as illustrated in FIG. 2A, among light beams emitted from thedisplay part 21, a light beam reaching the visually recognizable area Acis defined as a light beam Lc.

The display part 21 displays an image on the basis of control of thecontroller 23. As the display part 21, for example, a liquid crystaldisplay with a backlight, an organic light-emitting diode, a plasmadisplay, or the like can be used. In addition, as the display part 21,an image may be generated using a screen that diffuses or reflectslight, and a projector or a scanning laser.

The display part 21 can display various types of information such as,for example, a road guidance display, a distance to a vehicle ahead, aremaining battery level of the vehicle, and a current vehicle speed. Thedisplay part 21 allows the observer D to visually recognize the goodvirtual image Iv by displaying display pixels having plurality ofwavelengths shifted in advance for each display position in accordancewith chromatic aberration generated in a projection optical system 22.

As illustrated in FIG. 3 , the display part 21 has a displayable area 21a larger in the up-down direction than an image Pc to be displayed. Bycontrolling pixels to be caused to emit light by the controller 23, adisplay position of the image Pc can be adjusted in the up-downdirection. FIG. 3 illustrates an arrow for guiding a destination as anexample of the image Pc.

As illustrated in FIGS. 2A and 2B, the projection optical system 22includes, for example, a lens 31 having a light condensing action and amirror 33. The projection optical system 22 enlarges the image displayedon the display part 21 and projects the enlarged image on the windshield5. Therefore, a size of a screen of the display part 21 can be reduced.In addition, the mirror 33 is large enough to reflect all the imagesprojected from the display part 21.

The opening 24 a is formed in an upper part of the case 24. Thetransparent member 25 is a member that covers this opening 24 a. Thetransparent member 25 is made of resin such as, for example,polyethylene terephthalate (PET). The transparent member 25 has atransmittance of about 50% to 90% and a reflectance of about 10% to 50%.The transparent member 25 is disposed on an optical path between theprojection optical system 22 and the windshield 5. The light reflectedby the mirror 33 passes through the transparent member 25 and reachesthe windshield 5. In the windshield 5, an area where the image of thedisplay part 21 is projected and reflected is defined as a reflectionarea Ra. The transparent member 25 transmits part of incident light andreflects part of the light. The transparent member 25 has apredetermined curvature.

The wall part 13 is provided with the light source part 15. Lightemission of the light source part 15 is controlled by the controller 23.The light source part 15 is, for example, an LED, and is an opticalelement having a divergence angle. As a result of narrowing the lightflux from the light source part 15 by curvatures of the transparentmember 25 and the windshield 5, a range of the light flux from the lightsource part 15 only needs to be wider than the visually recognizablearea Ac, and thus, the divergence angle is, for example, about 60°.

The light Lg emitted from the light source part 15 is reflected by thetransparent member 25 so as to become a light beam corresponding to adepression angle when the virtual image at a desired position is viewedfrom an inside of the visually recognizable area Ac, and reaches thewindshield 5. The light Lg that has reached the windshield 5 isreflected inside the reflection area Ra of the windshield 5 and reachesthe visually recognizable area Ac. In this manner, a shape of thetransparent member 25 and a position of the light source part 15 aredesigned corresponding to a shape of the windshield 5 so that the lightLg emitted from the light source part 15 is reflected by the transparentmember 25 and the windshield 5 to reach the visually recognizable areaAc. As illustrated in FIG. 2B, the light Lg from the light source part15 reaches a height of each eye of the observer D. A bright spot of thelight Lg serve as a reference for the observer D to calibrate theposition of the virtual image Iv.

An operation part 11 is a member for inputting an operation instructionfrom the observer D. An operation signal corresponding to an operationamount of the observer D is transmitted from the operation part 11 tothe controller 23. The operation part 11 is, for example, a button, acursor key, a remote controller, a touch panel, or the like.

Controller 23 can be implemented by a circuit including a semiconductorelement or the like. The controller 23 can be configured by, forexample, a microcomputer, a CPU, an MPU, a GPU, a DSP, an FPGA, or anASIC. The controller 23 reads data and programs stored in a built-instorage 23 a and performs various types of arithmetic processing,thereby implementing predetermined functions.

The storage 23 a is a storage medium that stores the programs and thedata necessary for implementing the functions of the controller 23. Thestorage 23 a can be realized by, for example, a hard disk (HDD), an SSD,a RAM, a DRAM, a ferroelectric memory, a flash memory, a magnetic disk,or a combination thereof.

The storage 23 a stores a plurality of pieces of image data representingthe virtual image Iv. The controller 23 determines the virtual image Ivto be displayed on the basis of vehicle-related information acquiredfrom an outside. The controller 23 reads the image data of thedetermined virtual image Iv from the storage 23 a and outputs the imagedata to the display part 21.

[1-1-2. Calibration of Virtual Image Position]

Next, differences between a conventional head-up display system and thehead-up display system of the present disclosure will be described. Inthe conventional head-up display system, it is necessary to adjust aheight of the visually recognizable area Ac in the up-down direction inaccordance with the height of the eye of the observer D. In theconventional head-up display system, the visually recognizable area Acis displaced by rotating the mirror 33. However, when the mirror 33 isrotated, the depression angle of the virtual image Iv viewed from theobserver D is changed, so that a deviation occurs in superimpositionbetween the outside world and the image, and the position of virtualimage Iv may deviate, depending on the height of the eye of the observerD.

In the head-up display system 1 of the first embodiment, a width in aheight direction of the visually recognizable area Ac is increased byincreasing a display area of the display part 21 instead of adjusting atilt angle of the mirror 33. As a result, while as illustrated in FIG. 4, the virtual image Iv can be viewed at the same position at any heightof the eye, it is necessary to calibrate in which area of thedisplayable area 21 a of the display part 21, whose image is illustratedin FIG. 3 , is to be displayed. For example, as illustrated in FIG. 4 ,in a case where a range Ap on which the image is to be superimposed isset on a traveling road surface 51 away from the vehicle 3 by anarbitrary distance, the position of the virtual image Iv may deviate inthe up-down direction to the height of the eye of the observer D becausea virtual image displayable range 19 and the visually recognizable areaAc are wide.

Therefore, by displaying a calibration image Pg as illustrated in FIG. 5from the display part 21 and turning on the light source part 15provided on the wall part 13 as illustrated in FIGS. 2A and 2B, thelight from the light source part 15 is matched with a reference point Prof the calibration image Pg, so that video can be matched with a centerof the range to be superimposed.

In the case of a state illustrated in FIG. 5 , a bright spot 15 c fromthe light source part 15 viewed by the observer D and the referencepoint Pr that is a center of the calibration image Pg deviate from eachother. The bright spot 15 c is reference light for calibration. Asillustrated in FIG. 6 , the observer D adjusts the area where the imageis displayed in the displayable area 21 a of the display part 21 inaccordance with an instruction from the operation part 11, and thecalibration image Pg is moved, so that the reference point Pr is matchedwith the bright spot 15 c from the light source part 15.

Next, a flow of the calibration of the virtual image display will bedescribed with reference to FIG. 7 .

When the observer D gives an operation instruction through the operationpart 11, the calibration of the virtual image Iv is started.

In step S1, upon receiving an instruction to start calibration from theoperation part 11, the controller 23 shifts to a calibration mode andturns on the light source part 15 to emit the light Lg. The light Lgthat has emitted from the light source part 15 is reflected by thetransparent member 25 and reaches the windshield 5, and is reflectedinside the reflection area 5 a of the windshield 5 and reaches thevisually recognizable area Ac.

In step S2, in the calibration mode, the controller 23 switches thedisplay image displayed on the display part 21 to the calibration imagePg and displays the calibration image Pg. The display part 21 displaysthe calibration image Pg in a partial area of the displayable area 21 a.The displayed calibration image Pg is enlarged by the lens 31, reflectedby the mirror 33 toward the windshield 5, reflected inside thereflection area 5 a of the windshield 5, and reaches the visuallyrecognizable area Ac.

In step S3, the observer D determines whether or not the bright spot 15c of the light Lg from the light source part 15 matches the referencepoint Pr of the calibration image Pg. As illustrated in FIG. 5 , whenthe observer D determines that the bright spot 15 c by the light Lg fromthe light source part 15 does not match the reference point Pr of thecalibration image Pg (No in S3), the observer D operates the operationpart 11 to adjust an upper-lower position of the calibration image Pg sothat the reference point Pr of the calibration image Pg matches thebright spot 15 c in step S4. The controller 23 can move the calibrationimage Pg in the up-down direction by displacing the display area of thedisplay part 21 in accordance with the operation signal of thisoperation part 11.

By this operation, when the observer D determines that the bright spot15 c by the light Lg from the light source part 15 matches the referencepoint Pr of the calibration image Pg (Yes in S3), the observer D inputsa calibration completion instruction to the operation part 11 in stepS5.

Upon receiving a signal indicating the calibration completioninstruction from the operation part 11, the controller 23 turns off thelight source part 15 and stops the emission of the light Lg in step S6.

In step S7, the controller 23 causes the storage 23 a to store thedisplay area of the calibration image Pg in the display part 21,terminates the calibration mode, and displays the image Pc to be thevirtual image Iv in this display area of the display part 21.

[1-2. Effects and the Like]

The head-up display system 1 of the present disclosure includes thedisplay part 21 that emits the light flux visually recognized by theobserver D as the virtual image Iv, the projection optical system 22that guides the light flux to the windshield 5, the light source part 15that emits the light, the operation part 11 for adjusting the positionof the virtual image Iv in the longitudinal direction, and thecontroller 23 that controls the display area of the display part 21 inaccordance with an operation of the operation part 11 by the observer.The light flux emitted from the display part 21 is reflected by thewindshield 5 and reaches the visually recognizable area Ac where theobserver D can visually recognize the virtual image Iv. The light fluxof the light Lg that has emitted from the light source part 15 isreflected inside the reflection area Ra of the windshield 5 and reachesthe visually recognizable area Ac. The virtual image and the light Lgfrom the light source part 15 can be visually recognized in asuperimposed manner.

The light Lg that is emitted from the light source part 15, which is alight source different from the display part 21, and serves as areference for the calibration of the position of the virtual image Iv isreflected in the reflection area Ra of the windshield 5 where the imagefrom the display part 21 as the virtual image is reflected. This lightLg is corrected to become the light beam corresponding to the depressionangle when the virtual image Iv at a desired position is viewed from theinside of the visually recognizable area Ac. Consequently, even if theeye position of the observer D changes in the up-down direction, thedisplay area of the display part 21 can be adjusted on the basis of thelight Lg from the light source part 15, so that a positionalrelationship between the virtual image Iv and a scene of the outsideworld from the windshield 5 can be adjusted to a desired positionalrelationship. Therefore, the position of the virtual image Iv can beadjusted in accordance with the height of the eye of the observer D, andthe superimposition deviation between the real view of the outside worldand the virtual image Iv can be reduced.

Note that the wall part 13 is not limited to the plate-shaped member,and may be a box-shaped member. In this case, the light source part 15may be accommodated in the wall part 13, and the light Lg emitted fromthe light source part 15 may be directed to the transparent member 25through a through-hole provided in a surface of the wall part 13. Inaddition, the light source part 15 may be embedded and fixed in theplate-shaped wall part 13.

Furthermore, the light source part 15 may be disposed on the transparentmember 25 instead of the wall part 13. The light Lg that has emittedfrom the light source part 15 disposed in the transparent member 25 isreflected in the reflection area Ra of the windshield 5 and is directedto the visually recognizable area Ac.

In addition, in the calibration mode, the controller 23 may cause thedisplay part 21 to display the image Pc instead of displaying thecalibration image Pg, and adjust the position of the virtual image Iv ofthe image Pc with respect to the bright spot 15 c of the light sourcepart 15 by moving the image Pc in the displayable area 21 a of thedisplay part 21 in accordance with the operation amount of the observerD. When the position of the image Pc or the calibration image Pg isadjusted, the positions in the optical member and the windshield 5 wherethe light beam Lc constituting the image Pc or the calibration image Pgis transmitted and reflected change in accordance wi_(t)h the displayposition of the image Pc or the calibration image Pg. Therefore, thevirtual image Iv resulting from projecting the image Pc or thecalibration image Pg may be distorted. Since this distortion can bepredicted in accordance with the display position of the image Pc or thecalibration image Pg, a correction parameter may be stored in thestorage 23 a. In order to correct the distortion of the virtual image Ivin accordance with the display position of the image Pc or thecalibration image Pg, the controller 23 may acquire the correctionparameter stored in the storage 23 a and correct the image Pc or thecalibration image Pg.

Second Embodiment

In the first embodiment, the light source part 15 is disposed on thewall part 13. In a second embodiment, the light source part 15 isdisposed in a HUD device 9A. Configurations other than this point andpoints described below are common between the head-up display system 1and the HUD device 9 of the first embodiment and a head-up displaysystem 1A and the HUD device 9A of the second embodiment.

FIG. 8 is a schematic view illustrating a configuration of the head-updisplay system 1A in the second embodiment.

In the second embodiment, the light source part 15 is disposed insidethe HUD device 9A, and the light Lg from the light source part 15 isreflected inside the projection optical system 22. For example, thelight Lg emitted from the light source part 15 is reflected by the lens31 toward the mirror 33, and further, the light Lg reflected by themirror 33 is transmitted through the transparent member 25, is reflectedinside the reflection area Ra of the windshield 5, and reaches thevisually recognizable area Ac. In this manner, the position of the lightsource part 15 with respect to the projection optical system 22 isdesigned corresponding to the shape of the windshield 5 so that thelight Lg emitted from the light source part 15 is reflected inside theprojection optical system 22, reflected by the windshield 5, and reachesthe visually recognizable area Ac.

In this manner, even in the configuration in which the light source part15 is disposed inside the HUD device 9A and the light Lg from the lightsource part 15 is reflected inside the projection optical system 22 andreaches the visually recognizable area Ac, it is possible to obtain thesame effects as those of the first embodiment.

Third Embodiment

In the second embodiment, the light Lg from the light source part 15 isreflected inside the projection optical system 22. In a thirdembodiment, the light Lg from the light source part 15 is reflected bythe display part 21. Configurations other than this point and pointsdescribed below are common between the head-up display system 1A and theHUD device 9A of the second embodiment and a head-up display system 1Band a HUD device 9B of the third embodiment.

FIG. 9 is a schematic view illustrating a configuration of the head-updisplay system 1B in the third embodiment.

In the third embodiment, the light source part 15 is disposed inside theHUD device 9B, and the light Lg from the light source part 15 isreflected by the display part 21. The light Lg emitted from the lightsource part 15 is reflected by the display part 21, is transmittedthrough the lens 31, is further reflected by the mirror 33, istransmitted through the transparent member 25, is then reflected insidethe reflection area Ra of the windshield 5, and reaches the visuallyrecognizable area Ac.

In this manner, even in the configuration in which the light source part15 is disposed inside the HUD device 9B and the light Lg from the lightsource part 15 is reflected by the display part 21 and reaches thevisually recognizable area Ac, it is possible to obtain the same effectsas those of the first embodiment.

Fourth Embodiment

A fourth embodiment is a configuration in which an optical element 41 isdisposed between the light source part 15 and the projection opticalsystem 22 in the head-up display system 1A of the second embodiment.Configurations other than this point and points described below arecommon between a head-up display system 1C and a HUD device 9C of thefourth embodiment and the head-up display system 1A and the HUD device9A of the second embodiment.

FIG. 10 is a schematic view illustrating a configuration of the head-updisplay system 1C in the fourth embodiment.

In the fourth embodiment, the light source part 15 and the opticalelement 41 are disposed inside the HUD device 9C, and the light Lgemitted from the light source part 15 is transmitted through the opticalelement 41 and is reflected by the lens 31. The optical element 41 is,for example, a lens having a light condensing action. The opticalelement 41 is configured of one or a plurality of optical members suchas a lens and a mirror as necessary. The light Lg emitted from the lightsource part 15 is transmitted through the optical element 41, reflectedby the lens 31, and further reflected by the mirror 33. The light Lgreflected by the mirror 33 is transmitted through the transparent member25, and is then reflected inside the reflection area Ra of thewindshield 5 and reaches the visually recognizable area Ac. Note thatthe light Lg emitted from the light source part 15 may be transmittedthrough the optical element 41 and be reflected by the display part 21instead of being transmitted through the optical element 41 and beingreflected by the lens 31.

In this manner, since the optical element 41 is disposed between thelight source part 15 and the projection optical system 22, the light ofthe light source part 15 can be corrected. That is, since a degree offreedom in design is improved,-it is possible to obtain the same effectsas those of the first embodiment while improving quality of the virtualimage Iv.

Fifth Embodiment

A fifth embodiment is a configuration in which the light source part 15is movable in the head-up display system 1 of the first embodiment.Configurations other than this point and points described below arecommon between a head-up display system 1D of the fifth embodiment andthe head-up display system 1 of the first embodiment.

FIG. 11 is a schematic view illustrating a configuration of the head-updisplay system 1D in the fifth embodiment. The light source part 15 isattached to the wall part 13 so as to be displaceable toward thetransparent member 25. The optical element 41 is disposed on an opticalpath between the light source part 15 and the transparent member 25. Atthe time of calibration of the virtual image Iv, the controller 23controls the movement of the light source part 15 from an accommodationposition Ps1 indicated by a broken line of the wall part 13 to acalibration position Ps2 suitable for calibration, for example, using amotor and a rack-and-pinion mechanism. Therefore, when the calibrationof the virtual image Iv ends, the light source part 15 is returned tothe accommodation position Ps1 of the wall part 13. As a result, thecalibration can be appropriately performed regardless of the position ofthe wall part 13 and the shape of the transparent member 25.

Note that the optical element 41 may be displaceable instead of thelight source part 15 being displaceable. Furthermore, in a case wherethe light source part 15 is displaceable, the optical element 41 may beomitted.

Sixth Embodiment

A sixth embodiment is a configuration in which the light source part 15includes a plurality of optical elements in the head-up display system 1of the first embodiment. Configurations other than this point and pointsdescribed below are common between a head-up display system 1E of thesixth embodiment and the head-up display system 1 of the firstembodiment.

FIG. 12 is a schematic view illustrating a configuration of the head-updisplay system 1E in the sixth embodiment. FIG. 13 is an enlarged viewof a light source part 15E.

The light source part 15E has a plurality of optical elements 15 a. Eachof the optical elements 15 a emits light having directivity. The opticalelement 15 a is, for example, a laser element. Each of the opticalelements 15 a has a different light irradiation direction. As a result,it is possible to change the visible optical element 15 a in accordancewith the height of the eye of the observer D. In this manner, byappropriately designing a position and a projection direction of each ofthe optical elements 15 a, the observer D can visually recognize thereference light for calibration according to the height of the eye, sothat the virtual image Iv can be adjusted to an appropriate position.

Furthermore, in order to impart directivity to the light emitted fromeach of the optical elements 15 a, as illustrated in FIG. 14 , a wallpart 13F may have a cylindrical part 13 a extending along an emissiondirection of each of the optical elements 15 a. The cylindrical part 13a has a cylindrical shape. Since light emitted from each of the opticalelements 15 b of a light source part 15F has directivity as a result ofbeing limited by the cylindrical part 13 a, it is possible to change thevisible optical element 15 b in accordance with the height of the eye ofthe observer D. Consequently, the observer D can visually recognize thecalibration reference light in accordance with the height of the eye, sothat the virtual image Iv can be adjusted to an appropriate position. Inaddition, since the cylindrical part 13 a is provided, the opticalelement 15 b need not have directivity and need not have a largediffusion angle.

Furthermore, the member that imparts directivity to the light emittedfrom the optical element 15 b may have a form as illustrated in FIG. 15. The wall part 13F includes a support plate 13 c that supports theplurality of optical elements 15 b, and a light shielding plate 13 bhaving through-holes 13 b a formed so that light from each of theoptical elements 15 b advances in different emission directions. Withthis configuration, since light emitted from each of the opticalelements 15 b of the light source part 15F has directivity as a resultof being limited by each of the through-holes 13 ba, it is also possibleto change the visible optical element 15 b in accordance with the heightof the eye of the observer D. Consequently, the observer D can visuallyrecognize the reference light of the calibration in accordance with theheight of the eye, so that the virtual image can be adjusted to anappropriate position.

Other Embodiments

As described above, the above embodiments have been described asexamples of the technology disclosed in the present application.However, the technique in the present disclosure is not limited thereto,and can also be applied to embodiments in which changes, replacements,additions, omissions, and the like are made as appropriate. Therefore,other embodiments will be exemplified below.

In the above embodiments, the case where the head-up display system 1 isapplied to the vehicle 3 such as an automobile has been described.However, an object to which the head-up display system 1 is applied isnot limited to the vehicle 3. The object to which the head-up displaysystem 1 is applied may be, for example, a train, a motorcycle, a ship,or an aircraft, or may be an amusement machine without movement. In thecase of an amusement machine, the light flux from the display part 21and the light from the light source part 15 are reflected on atransparent curved plate as the window part that reflects the light fluxemitted from the display part 21 instead of the windshield 5. Further,the real view that can be virtually recognized by the user through thetransparent curved plate may be video displayed from another videodisplay device. That is, the virtual image by the head-up display system1 may be superimposed and displayed on the video displayed from theother image display device.

While in the above embodiments, the opening 24 a of the HUD 9 isdisposed along the upper surface of the dashboard 7, the presentinvention is not limited thereto. As illustrated in FIG. 16 , the HUD 9may be disposed below an upper surface 7 a of the dashboard 7. A hole 7b through which the light Lc and the light Lg from the HUD 9 and thelight source part 15 pass is formed on the upper surface of dashboard 7.The wall part 13 extends upward from an upper surface of the HUD 9, andthe light source part 15 is attached to the wall part 13. The wall part13 and the light source part 15 are also disposed below the uppersurface 7 a of the dashboard 7.

Outline of Embodiments

(1) A head-up display system of the present disclosure is a head-updisplay system that displays a virtual image superimposed on a real viewthat can be visually recognized through a window part, the head-updisplay system including: a display part that emits a light flux to bevisually recognized by an observer as the virtual image; an opticalsystem that guides the light flux to the window part; a light sourcepart that emits light; an operation part for adjusting a position of thevirtual image in a vertical direction; and a controller that controls adisplay area of the display part in accordance with an operation of theoperation part by the observer, wherein the light flux emitted from thedisplay part is reflected by the window part and reaches a visuallyrecognizable area where the observer can visually recognize the virtualimage, the light emitted from the light source part is reflected insidean area where the light flux is reflected by the window part and reachesthe visually recognizable area, and the virtual image and the light fromthe light source part are superimposed, and can be visually recognized.

Consequently, even if the position of the eye of the observer changes inthe up-down direction, the display area of the display part can beadjusted on the basis of the light from the light source part, so that apositional relationship between the image and a scene of the outsideworld from the window part can be adjusted to a desired positionalrelationship. Therefore, the position of the virtual image can beadjusted in accordance with the height of the eye of the observer, andthe superimposition deviation between the real view of the outside worldand the virtual can be reduced.

(2) The head-up display system in (1) includes a transparent member thatis installed on an optical path between the optical system and thewindow part, and through which the light flux from the display part istransmitted, wherein the light from the light source part is transmittedthrough the transparent member and enters the window part.

(3) The head-up display system in (1) includes a transparent member thatis installed on an optical path between the optical system and thewindow part, and through which the light flux from the display part istransmitted, wherein the light from the light source part is reflectedby the transparent member and enters the window part.

(4) In the head-up display system in (3), the light source part isprovided on a wall part between the window part and the transparentmember.

(5) In the head-up display system in any one of (1) to (4), the displaypart displays a calibration image for calibration.

(6) In the head-up display system in (5), the calibration image has areference point for matching the light from the light source part.

(7) In the head-up display system in (5) or (6), the controller switchesa display image displayed on the display part to the calibration imagein a calibration mode.

(8) In the head-up display system in any one of (1) to (7), thecontroller moves the calibration image or the display image in adisplayable area of the display part in the calibration mode.

(9) In the head-up display system in (8), the controller moves thecalibration image or the display image in the displayable area andcorrects distortion of the virtual image.

(10) In the head-up display system in any one of (5) to (9), thecontroller causes a storage to store a display area of the calibrationimage for which the calibration has been completed in the display part,and causes the display part to display the display image in this storeddisplay area in the display part.

(11) In the head-up display system in any one of (1) to (10), thecontroller causes the light source part to move from an accommodationposition to a calibration position in the calibration mode.

(12) In the head-up display system in any one of (1) to (11), the windowpart is a windshield of a moving body. Thus, the present invention canbe applied as a head-up display system of a moving body.

(13) In the head-up display system in any one of (1) to (12), the lightsource part includes: a plurality of light sources; and a tubular partthat limits an emission direction and a divergence angle of lightemitted from each of the plurality of light sources to make the emissiondirections and the divergence angles from one another.

The present disclosure can be applied to a head-up display system thatdisplays a virtual image in a front of a window part.

EXPLANATIONS OF LETTERS OR NUMERALS

1, 1A, 1B, 1C, 1D, 1E head-up display system

3 vehicle

5 windshield

7 dashboard

9, 9A, 9B, 9C head-up display device (HUD device)

11 operation part

13, 13F wall part

13 a cylindrical part

13 b light shielding plate

13 ba through-hole

13 c support plate

15, 15E, 15F light source part

15 a, 15 b optical element

15 c bright spot

19 virtual image displayable range

21 display part

21 a displayable area

22 projection optical system

23 controller

23 a storage

24 case

24 a opening

25 transparent member

31 lens

33 mirror

41 optical element

Ac visually recognizable area

Iv virtual image

Pc image

Pg calibration image

Ra reflection area

What is claimed is:
 1. A head-up display system that displays a virtualimage superimposed on a real view that can be visually recognizedthrough a window part, the head-up display system comprising: a displaypart that emits a light flux to be visually recognized by an observer asthe virtual image; an optical system that guides the light flux to thewindow part; a light source part that emits light; an operation part foradjusting a position of the virtual image in a vertical direction; and acontroller that controls a display area of the display part inaccordance with an operation of the operation part by the observer,wherein the light flux emitted from the display part is reflected by thewindow part and reaches a visually recognizable area where the observercan visually recognize the virtual image, the light emitted from thelight source part is reflected inside an area where the light flux isreflected by the window part and reaches the visually recognizable area,and the virtual image and the light from the light source part aresuperimposed, and can be visually recognized.
 2. The head-up displaysystem according to claim 1, comprising a transparent member that isinstalled on an optical path between the optical system and the windowpart, and through which the light flux from the display part istransmitted, wherein the light from the light source part is transmittedthrough the transparent member and enters the window part.
 3. Thehead-up display system according to claim 1, comprising a transparentmember that is installed on an optical path between the optical systemand the window part, and through which the light flux from the displaypart is transmitted, wherein the light from the light source part isreflected by the transparent member and enters the window part.
 4. Thehead-up display system according to claim 3, wherein the light sourcepart is provided on a wall part between the window part and thetransparent member.
 5. The head-up display system according to claim 1,wherein the display part displays a calibration image for calibration.6. The head-up display system according to claim 5, wherein thecalibration image has a reference point for matching the light from thelight source part.
 7. The head-up display system according to claim 5,wherein the controller switches a display image displayed on the displaypart to the calibration image in a calibration mode.
 8. The head-updisplay system according to claim 1, wherein the controller moves thecalibration image or the display image in a displayable area of thedisplay part in the calibration mode.
 9. The head-up display systemaccording to claim 8, wherein the controller moves the calibration imageor the display image in the displayable area and corrects distortion ofthe virtual image.
 10. The head-up display system according to claim 5,wherein the controller causes a storage to store a display area of thecalibration image for which the calibration has been completed in thedisplay part, and causes the display part to display the display imagein this stored display area in the display part.
 11. The head-up displaysystem according to claim 1, wherein the controller causes the lightsource part to move from an accommodation position to a calibrationposition in the calibration mode.
 12. The head-up display systemaccording to claim 1, wherein the window part is a windshield of amoving body.
 13. The head-up display system according to claim 1,Wherein the light source part includes: a plurality of light sources;and a tubular part that limits an emission direction and a divergenceangle of light emitted from each of the plurality of light sources tomake the emission directions and the divergence angles different fromone another.
 14. The head-up display system according to claim 2,wherein the display part displays a calibration image for calibration.15. The head-up display system according to claim 3, wherein the displaypart displays a calibration image for calibration.
 16. The head-updisplay system according to claim 4, wherein the display part displays acalibration image for calibration.
 17. The head-up display systemaccording to claim 6, wherein the controller switches a display imagedisplayed on the display part to the calibration image in a calibrationmode.
 18. The head-up display system according to claim 14, wherein thecontroller moves the calibration image or the display image in adisplayable area of the display part in the calibration mode.
 19. Thehead-up display system according to claim 15, wherein the controllermoves the calibration image or the display image in a displayable areaof the display part in the calibration mode.
 20. The head-up displaysystem according to claim 16, wherein the controller moves thecalibration image or the display image in a displayable area of thedisplay part in the calibration mode.